The 7-4 ruling by the U.S. 9th Circuit Court of Appeals found that the U.S. Forest Service violated federal endangered species protections by approving the mining practice along the Klamath without consulting wildlife officials. The Klamath starts in southeastern Oregon and empties into the Pacific Ocean about 40 miles south of the California-Oregon border.

Friday's decision, which overturned rulings by a district court and a three-judge appeals' panel, came in response to a lawsuit filed by the Karuk Tribe. The Northern California tribe challenged the Forest Service's 2004 approval of suction dredge mining, contending it harmed coho salmon, a threatened species under the Endangered Species Act. Suction dredges pump sand and gravel from riverbeds, which environmentalists say clouds rivers and disturbs habitat and spawning of trout and salmon.

Judge William A. Fletcher, writing for the majority, said federal law required the Forest Service to consult wildlife agencies before approving activity that might harm an imperiled species. The required review will delay approval for mining operations in endangered species habitat in the circuit's nine states.

In the dissent, Judge Milan D. Smith Jr. complained that the decision would reduce jobs in the region and effectively end suction dredge gold mining. He said California issued about 3,500 permits for such mining in 2008, and 18% of those miners received a significant portion of their income from dredging.

"By rendering the Forest Service impotent to meaningfully address low impact mining, the majority effectively shuts down the entire suction dredge mining industry in the states within our jurisdiction," Smith wrote. Miners, he added, "will simply give up, and curse the 9th Circuit."

California, in response to a state lawsuit, has already imposed a moratorium on suction dredge mining. But the 9th Circuit noted that the state ban was temporary and failed to prohibit other kinds of gold mining along the river. As recently as December, the Forest Service approved mining activities in coho salmon critical habitat along the Klamath without consulting wildlife experts, the 9th Circuit said.